Toxicity Assessment of Anthracene and Oleic Acid-Coated Magnetite Nanoparticles to Embryos and Larvae of Rhinella arenarum

PARRA, MARIA CAROLINA; VENTURINO, ANDRÉS; LASCANO, CECILIA INÉS

Congreso; SETAC Latin America 14th Biennial Meeting; 2021

SETAC

One of the main economic activities of the northern patagonic region in Argentina is oil and gas production, and polycyclic aromatic hydrocarbons (PAH) are consequently generated as pollutants. Oleic acid-coated magnetite nanoparticles (OA-NP) have been developed for use in the remediation process of PAH. The purpose of this work was to assess the toxicity of both anthracene (Ant; as representative of PAH) and OA-NP to a native amphibian species at its embryonic and larval developmental stages. Rhinella arenarum embryos were collected from the wild and maintained in laboratory facilities until they reached the appropriate developmental stage to be subjected to the tests. Individuals were exposed to different concentrations of Ant and OA-NP to establish toxicological parameters. Each concentration was tested by triplicate and each exposure was repeated at least three times. 72 h embryos and 10 days-old larvae were exposed for 96 h in modified Amphitox medium (containing a final concentration of 0,1 % v/v of acetone) in static conditions, keeping a ratio of 10 individuals in 100 mL of medium. Mortality and malformations were assessed daily. A logistic model was adjusted to mortality data by non-linear regression and the toxicological parameters LC50, LC10 and LC1 were calculated. Anthracene was toxic for both embryos and larvae. For embryos, the toxicological parameters calculated were: LC50-96h: 4.65 ± 0.15 mg/L; LC1: 2.08 mg/L; LC10: 3.16 mg/L. Toxicological parameters for larvae were: LC50: 4.85 ± 0.13 mg/L; LC1: 2.85 mg/L; LC10: 3.76 mg/L. Individuals exposed to Ant showed malformations such as edema, caudal fin folds, blistering and lacerations. OA-NP were neither toxic nor teratogenic to embryos and larvae in concentrations up to 10 mg/L. Both embryos and larvae ingested the OA-NP, which were detected in feces. Anthracene toxicity was similar for both embryos and larvae of R. arenarum, while OA-NP displayed low apparent toxicity. Preliminary analyses on oxidative stress showed no significant effects. Experiments to evaluate the toxicity of the combination between Ant and OA-NP will be carried out, and sublethal exposures will be conducted to assess the impact of Ant, OA-NP and their combination at the biochemical and molecular levels in R. arenarum embryos and larvae.